Slope, in roofing, is expressed or the rise (in inches) per 12 inches of run. For example, in the diagram below, we have a slope of 6 in 12. Why? Because the rise every 12” is 6” of the run. In other words, it rises half as fast as it runs.
Note: We get 1/3 by dividing both 12 and 36 into 12.
How to convert from Pitch to Slope
For example: Convert a pitch of 1/4 to slope